Modern locomotives typically include one or more crashworthy memory modules or “black boxes” that record and communicate information including voice and image data and vehicle performance parameters received from event recorders or locomotive control computers. Data retrieved from a crashworthy memory module after an accident involving a locomotive can help reconstruct and provide a detailed and accurate accounting of events leading up to and during the accident. Crashworthy memory modules, therefore, store the recorded information in a crash-hardened memory unit designed and built to withstand the severe conditions that may occur during the accident.
An accident involving a locomotive may include fires caused due to spillage of fuel from the locomotive or from railroad cars attached to or located near the accident scene. A crashworthy memory module may be subjected to temperatures as high as 1400° F. because of such fires. Crashworthy memory modules are designed to withstand such high temperatures and smolder temperature as high as 500° F. for 10 hours or more without allowing the high temperatures to adversely affect electronic data stored within the crashworthy memory module. Although the crashworthy memory module and electronic components within the crashworthy memory module are heavily insulated, heat may still enter the crashworthy memory module through electrical wires connecting the electronic components within the crashworthy memory module to locomotive subsystems located outside the crashworthy memory module. To prevent damage to the electronic components that store data within the crashworthy memory module, it is important to prevent the heat from the fire from being conducted by the wires to the electronic components in the crashworthy memory module.
One attempt to address some of the problems described above is disclosed in U.S. Pat. No. 7,703,291 of Bushnik et al. that issued on Apr. 27, 2010 (“the '291 patent”). In particular, the '291 patent discloses an environmental control system for a hard drive of an event recorder. The disclosed thermoelectric module transfers heat between the hard drive and a housing of the event recorder, in response to an applied voltage, in order to maintain a hard drive temperature within a hard drive operable temperature range. The '291 patent also discloses an active thermoelectric controller for actively drawing heat away from the hard drive and out of the housing. The thermoelectric controller can include a heat sink coupled to the thermoelectric module and to the housing for dissipating heat from the thermoelectric module to the housing.
Although the '291 patent discloses a system for controlling the temperature of a hard drive of an event recorder, the disclosed system may still be inadequate. For example, the system of the '291 patent requires an applied voltage to control the hard drive temperature. After an accident, however, equipment which provides the applied voltage may not function rendering the thermal control system of the '291 patent inadequate. Further, the system of the '291 patent may not be able to prevent heat from a fire outside the event recorder from entering the event recorder through wires connected to the hard drive.
The crashworthy memory module of the present disclosure solves one or more of the problems set forth above and/or other problems in the art.